Fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone plus rituximab and granulocyte‐macrophage–colony stimulating factor (GM‐CSF) alternating with methotrexate and cytarabine plus rituximab and GM‐CSF in patients with Richter syndrome or fludarabine‐refractory chronic lymphocytic leukemia

Abstract

BACKGROUND Therapy for patients with Richter syndrome (RS) or fludarabine‐refractory chronic lymphocytic leukemia (CLL) is unsatisfactory. A Phase II study was conducted to evaluate an alternating combination cytotoxic regimen given with rituximab and granulocyte‐macrophage–colony stimulating factor (GM‐CSF) in these patients. METHODS Fludarabine‐refractory CLL was defined as failure to respond to most recent prior fludarabine‐containing regimen. Patients received up to six cycles of fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone (hyper‐CVXD) plus rituximab and GM‐CSF alternating with methotrexate and cytarabine plus rituximab and GM‐CSF. Response, toxicity, and survival data were compared with data from prior therapy with hyper‐CVXD alone in this patient group. RESULTS Forty‐nine patients with RS (n = 30 patients) or refractory CLL (n = 19 patients) were treated on study. Nine patients (18%) achieved a complete remission, and 11 patients achieved a partial remission (22%), for an overall objective response (OR) rate of 41%. With a median follow‐up of 7.5 months and a maximum follow‐up of 15.2 months, the 12‐month failure free survival (FFS) rate was 27%, and the overall survival (OS) rate was 39%. Nine patients (18%) died during the first cycle of therapy, and two patients (4%) died during the second cycle. There were no significant differences between the rates of OR, OS, and FFS in the current study and those obtained with hyper‐CVXD alone on a prior study. CONCLUSIONS The study regimen had activity and significant toxicity in patients with RS or fludarabine‐refractory CLL. It was not clearly better compared with hyper‐CVXD alone in this patient population. Cancer 2003;97:1711–20. © 2003 American Cancer Society. DOI 10.1002/cncr.11238